Submarine detection



Patented June 18, 1946 SUBMARINE DETECTION De Witt R. Goddard,Riverhead, N. Y., assigner' to Radio Corporation of America, acorporationv of Delaware Application August 30, 1943, Serial No. 500,479

2 claims. (ci. 177-386) 1 'I'his invention relates to a new and improvedmethod of submarine detection. An object of this invention is to providethe means for eficient submarine detection having greater effectiverange than, as far as I am aware,

methods heretofore employed.

Another object of this invention is to produc a simple device to detectthe presence of submarines or other submerged objects over greatdistances.

A feature of this invention is the` employment of both high explosivecharges to generate sound waves and electrical means to time the echo ofthe sound returning from the submerged object.

The operation of the invention depends upon the idea of emitting a shortpulse or sound in the water close to the boat searching for submarinesand electrically recording the echo returning from the submarine.

The range of such equipment as used in the past has been limited due tothe fact that electrical devices of limited power have been used to.

generate the outgoing sounds.

According to my invention I propose to use small charges of highexplosive, thereby producing sound pulses in the water of far greaterpower or amplitude than has been possible in the past.

and will result in a greater effective range of submarine detection.

This invention will best be understood by referring to the accompanyingdrawing in which:

Fig. 1 shows an arrangement for discharging the explosive charges, and

Fig. 2 is a schematic diagram of the electrical recording devices.

Referring now to Fig. 1 of the drawing, a tube or magazine I has locatedtherein a plurality of small bombs 2. These small bombs have builtwithin their structure a small time fuse device and detonationarrangement similar to a Mills hand-grenade. The bombs 2 are located ina row within tube I and ejected by means of a plunger 3 containing aratchet portion B which is notched 2. notches 6 to discharge one bombfrom the end of the tube I. Such a discharged bomb is shown-at I4. Inthe operation .of a Mills hand grenade, the time fuse firing the chargeis ignited byV an explosive cap. 'This cap is fired by a spring actuatedstriking piece or hammer which is held in the cocked position away fromthe cap by means of a hook-shaped piece'of metal indicated in Fig. 1 asa detonating lever i5. This lever or hookshaped piece of metal extendsacross the top or head of the bomb and along the side of its body as isshown. According to this invention. the detonating lever is retained inthis position by the inside wall o'f the magazine. I. Normally whenV thehand grenades are used, the force of the hammer would throw oil thedetonating lever allowing the hammer to strike the explosive cap.'

ao thrown. the force released causes the detonating to move forward bythe pawl arrangement B on an armature 4. 'I'he armature 4 'is driven bythe solenoid 8 and movable core 8 which is connected to the armature bymeans of a link I0. A stop II is provided to limit the motion ofarmature 4 and a spring I2 insures the return of thet armature againststop I I. Armature 4 is pivoted at the lower portion by means of a pivotl. A stop Il is provided to limit the action of pawl 5. Y

In the operation of this device. each time that the solenoid 8 isenergized the plunger 3 is ad' However, this is kept from occurring by asuitably placed safety cotter pin and ring (not shown by the drawing).In manual operation, outside of a. magazine of this invention, the bodyof the grenade is grasped in the hand thereby holdingv` the leveragainst the grenade body in a manner similar to that mentioned above inconnection with the magazine. The ring which is attached to' the safetycotter pin is previously taken out. In this manual operation, the onlything keeping the detonating lever from flying olf is the v hand of theoperator. When the grenade. is

lever to fly oli! allowing the hammer to strike the explosive cap and afew seconds after the fuse has burned its full length, the grenade'explodes.

As mentioned. above, these bombs are built with a. detonatingarrangement which requires` thelever it to be released. The release oflever IBv is accomplished by holding the detonating lever l5 against the4body of the bomb and removing the safety cotter pin. Then the bomb ispushed into the forward end of the magazine I. The

bore of the magazine being of a suitable di ameter, keeps the lever I5against the body oi' the -the moment the bomb leaves the inside, of themagazine tube as shown at I6; Themagazine tube is positioned to extendover the stern of the boat so thatthebombs will drop in the water.. .Ilv

few seconds later the fuse ydischarges the .bomb which in the meantimehas sunk a few fathoms vanced the correct amount as determined by belowthe surface. The resulting high-intensity sound wave travels radially inall directions through the water. The sound wave is then kpicked up on arecording device 20 shown in Fig..

2 on board the ship. and provides a reference from which the time delaymay be determined. From this reference, the distance traveled by thesound waves and its reoccurring echoes may be determined.

In Fig. 2 the bomb discharger'is shown as being electrically connectedto an electrical timer 2i having a hand release button 22, a bell 23 andpickup devices 24 and 25. The timer periodically starts rotation oi! therecorder and also discharges a bomb into the water. The resultingexplosion is picked up by the two pickup microphones 24--25 which may belocated near the bow and stern of the boat respectively. Thesemicrophones record a mark on the recorder 20. Echoes from submergedobjects are also picked up by the microphones and make their marks on.the recorder chart. By knowing'the recorder chart 'speed and measuringthe distance between the initial mark yand the subsequent marks due toechoes, the distance and bearingl of submerged objects withinl the rangeof the apparatus may be ascertained.

f There are, of course, two possible bearings for each set of datalobtained, but this ambiguity may be removed by changing the course ofthe ship slightly and through the use of hand releas button 22discharging another bomb.

The bell rings each time a bomb is discharged so as to attract theattention of the manon watch in order that he may inspect the chart forsuspicious echoes.

While I have indicated and described a system of my invention, it willybe apparent toone skilled in the art that my invention is by no meanslimited to the particular devices shown and described, but that manymodiiicationsmay be made Without departing from the scope of myinvention. A

What I claim is:

l. A system for locating submerged objects comprising a tubular magazinecontaining 'a plurality of bombs of the type having an explosive timefuse detonating lever, each one of said bombs being arranged in a rowwithin said tubular magazine so that the release lever is'retainedinoperative thereby, a plunger rod having a pluyconnected to said timingsystem, a lpick-up device electrically'connected to said recordingdevice whereby the distance oi submerged objects can be determined bymeasuring the elapsedztime.

between the exploding of said ejected bomb and the returning echoes.

2. A ksystem for locating submerged objects including a tubular magazinecontaininga plurality'of bo'mbs ofthe type having an explosive time fusedetonating lever, each one of said bombs being successively arrangedwithin said magazine so that the detonating lever is retained inoperative thereby, a plunger rod having one end extending within saidtubular magazine, said plunger having a plurality of ratchet portionsfor periodically ejecting one of said bombs and thereby releasing saiddetonating lever so that the bomb automatically detonates apredetermined short time interval after ejection, a pivoted armaturelinked to said plunger rod, a pawl pivoted to said armature and arrangedto engage thev ratchet portion of said plunger rod,` an electricsolenoid, a movable core located within said sole'- noid and linked tosaid amature and forming part oi' a timing system, electric meansassociated with said timing system for periodically energising saidsolenoid/for actuating said. amature to'l eject one of said bombs, arecording device and a plurality ofV pick-up devices electricallyconnected to s/aid electric means whereby the distance oi'submergedobjects can be determined by measuring the elapsed time between theexplosion of said ejected bomb and the returning echoes. DE WITI' R.GODDARD.

